Stereo-isohypsograph.



E. VON OREL.

STEREO ISOHYPSOGRAPH.

APPLICATION FILED 1330.13, 1911.

1 ,090,4:94: Patented Mar. 17, 1914.

217mm I a? 515.6%

ZEDU Von ohm, or VIENNA, AUSTRIA-HUNGARY, ASSIGNOR iro run rim/i or cam. ZEISS, or JENA, GERMANY.

STEREO-ISOHYPSOGRAPH.

ease.

(application filed December 13, 1911. Serial No. 865,574.

To all whom it may concern Be it known that I, EnUARD'voN OREL, a citizen of Austria, residing at Vienna, Austria-Hungary, have invented a new and useful Stereo-Isohypsograph, of which the following is a specification.

The object of the present invention is to enable a single person to derive by mechanical means from a stereoscopic pair of photograms of a landscape a plan or map of the said landscape, principally in the form of a system of contour-lines (isohypsal lines), or particular points in the said landscape.

The new apparatus, which serves this purpose, is a combination of a stereo-comparator, a drawing device and a system of actuating devices, the said system bein accessible to the operator while looking 1i 1to the stereo -'comparator. These three principal parts are positively connected with each other in such a manner that the position of the pencil-point on'the surface of the drawing always corresponds to that point in the landscape which is indicated in the stereocomparator.

A'stereo-comparator is usually fitted with a double microscope, which is binocular or monocular and contains a mark in each of the two image-fields or in the common image-field respectively. An ordinary stereocomparator comprises further three slides, a height-slide a breadth-slide and a dept hslide. The height-slide causes a relative displacement of the microscope and the photograms in the height-direction of the latter, the breadth-slide just such a displacement n the breadth-direction of the photograms, while the depth-slide alters the distance apart of the photograms.

A triple slide system may serve as the drawing device. One of these slides, which shall be called the tracer height-slide, must change its location in accordancewith the position as to height, which theolyect-pomt to be plotted in the map occupies 1n the landscape. The other two slides are the tracerbreadth-slide and the tracer depthslide respectively. They move the pencil or the drawing surface in the breadth-direction and the depth-direction respectively. The tracer depth-slide is the carrier of both the tracer breadth-slide and the tracer heightslide. It is convenient to make the tracer breadth-slide the carrier of the pencil, when the drawing surface has a fixed position.

Specification of Letters Patent.

Patented Mar. 1?, 31914.

Generally speaking the place of the plane drawing surface may be taken by one that can be developed into a plane, 6. g. a cylindrical surface. For tracing isohypsal lines, two actuating devices controlling the apparatus in the breadth-direction and in the depth-direction respectively are sufficient for operating the apparatus, these actuating devices being adapted preferably to act on the drawing device. 4

The coupling between the stereo-comparator and the drawing device consists in a suitable positive connection of the three comparator slides on the one hand and of the three tracer slides on the other hand. When the two photograms are displaced by the comparator breadth-slide, the comparator depth-slide must be coupled with the tracer breadth-slide and the tracer depth-slide, and in such a manner that the distance apart of the photograms remains unaltered, when only the tracer breadth-slide, but not the tracer depth-slide as well, changes its locus. The coupling between the comparator depthslide and the tracer depth-slide is intended to displace the pencil-point from the zerodepth-line (the copy, o to speak, of the vertical plane laid through the base-line determined by the objectives used in taking the photograms) by an amount, which is the roduct derived from the len th of this base ine, the focal length of the said objectives, the scale of reduction of the copy and the reciprocal of the surplus, which the distance apart of the photograms, caused by the comparator depth-slide,shows,as compared with the minimum distance belonging to infinitely distant object-points (which indeed is never realized), parallax.

The comparator height-slide i to be coupled with the tracer height-slide and the tracer depth-slide in such a manner that the tracer height-slide is displaced (negatively or positively) from its zero-position. by an amount, which is the product derived from the (negative or positive) displacement of the comparator height-slide out of the zero-position, the reciprocal of the focal length of the objectives and the distance of the pencil-point from the zero-depth-line, the latter distance being the product derived from the distance of the point in the landscape from the base-line and the scale of reduction of the copy.

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. distance of the pencil-point from the zerodepth-line, the latter distance being the product derived from the distance of the point in the landscape from the base-line and the scale of reduction of the copy.

The annexed drawing represents a plan view of an apparatus for producing contourlines (a stereo-isohypsograph).

The double microscope a is the usual binocular one and is fitted with a mark in each image-field. It is carried by a fixed standard al the height-slide A carryingthe breadth-slide B and the depth-slide C, on

which latter slides the two photograms e are mounted. Studs m and n are attached to small slides m and n", which carry transverse slideways m and 113. In these slideways B and O are guided by means of pins. The studs m and n engage slots i and L in the shorter arms of levers i and k, which are pivoted at i and it. These levers, by means of slots in their longer arms, engage studs 0 and 7) respectively on the breadth-slide B which is carried by the depth-slide C. A bell-crank 9 engages the stud t of the slide A, and a rod 9 and a lever g serve for coupling the slide A with the slides A and C The dimensions of the members 9 and g are so chosen that the arrangement is equivalent to one, in which the shorter arm of the lever g engages the stud t directly.

The three levers q, i and is have in their zero-positions, in which they are parallel to the zero-breadth-line 13, equal operative arm-lengths Z and h, the former length being the focal length of the objectives used in taking the photograms e. B is fitted with the pencil f". At a distance h from the point of the said pencil the zero-depth-line C9 is located. The surface that can be covered by this pencil is indicated on the drawing board d by dotted lines. The slide A is fixed, by means of a set-screw w, in its zero-position, as the contour-line to be traced belongs to the same horizontal plane, in which the axes of the objectives were located, when the photograms were be ng taken. The slide B is likewise shown 1n its zero-position, in which distance between these two.

The breadth-slide.

the pencil-point lies in the zero-breadth-line B". A displacement of B causes a joint shifting of B and C Without a change in the Such a change only results from a displacement of 0 because the distance 0 p is shorter by a certain amount than the distance 6 70, vizrby the product derived from the base-line used when taking the photograms and the scale of the map. In order to be able to change the length of the said base-line or the said scale or both, the stud p for the lever is is not fitted directly to the breadth-slide B, but to an intermediate slide 39 having a clamping-screw 'w".

The breadth-slide B is displaced by means of a screw-spindle a: and the depthslide C by means of two screw-spindles 3 The spindle av receives its motion from a shaft 00 by means of a bevel-wheel 412 and of another bevel-wheel {82, the latter being mounted so as to slide longitudinally on the said shaft; By means of a chain-drive m the shaft m is coupled with the driving shaft proper in, which is accessible to the right hand of the copyist. The spindles y are coupled by means of their bevel-wheels 3 and 7 and a shaft g with bevel-wheels y and y. The left-hand spindle is connected by a chain-drive y" with the driving shaft yf, which lies to the left of the copyist.

I claim:

1. An apparatus for reproducing from a stereoscopic pair of photograms of a landscape amap of this landscape, comprising a stereo-comparator, a drawing device, means for positively coupling the stereo-comparator and said device together and a system of actuating devices controlling the said stereocomparator and drawing device, the said system being accessible to the operator while the latter is looking into the stem-- comparator.

2. The combination ofa stereo-comparator comprising three interdependent slides, a drawing device also comprising three interdependent slides A B and C of which A and B are carried by C, means for positively couplin the slides of the said stereocomparator with those of the said drawing device and a system of actuating devices controlling the said stere0comparator and the said drawing device, the saidsystem being accessible to the operator, while the latter is looking into the stereo-comparator. EDUARD VON OREL. Witnesses:

PAUL KRt'ienR, FRITZ SANDER. 

